Sensing performance of lead monoxide (PbO) doped tin oxide thick film gas sensor

Abstract

Abstract Gas sensors based on metal oxide nanostructures are in demand for the safety of human health and protection from environmental pollution. This type of sensors is more attractive in modern life for electronic devices because of low cast, more efficient, high reliability, fast response, more selective, and simplicity. In this paper we report undoped and PbO doped SnO2 thick film to study its microstructural and sensing behaviours. Three samples have been fabricated using screen printing technique on an alumina substrate and this is SnO2 (S1) and 1wt% PbO doped SnO2 (S2 and S3) at 800 0C and 900 0C. XRD and AFM techniques are used to observe the structural behaviours and it is found that the crystallite size decreases with PbO doping. The sensing properties such as sensing response, selectivity and transient time of the deposited thick films were studied at 200°C for various test gases such as ethanol, LPG and acetone concentrations (0–5000 ppm level). We also found that the response of sensor S3 to the test gas ethanol is ~ 3.38 times of LPG and ~ 1.95 times that of acetone. The response and recovery times of the ethanol gas for S3 sensor are 41s and 125s, respectively. Therefore, the deposited sensor S3 is a more suitable sensor for the test gas ethanol than LPG and acetone at 200 0C.